Cross join — cross_join.RPolarsDataFrame • tidypolars

Cross joins match each row in x to every row in y, resulting in a dataset with nrow(x) * nrow(y) rows.

Usage

# S3 method for class 'RPolarsDataFrame'
cross_join(x, y, suffix = c(".x", ".y"), ...)

# S3 method for class 'RPolarsLazyFrame'
cross_join(x, y, suffix = c(".x", ".y"), ...)

Arguments

x, y: Two Polars Data/LazyFrames
suffix: If there are non-joined duplicate variables in x and y, these suffixes will be added to the output to disambiguate them. Should be a character vector of length 2.
...: Not used.

Examples

test <- polars::pl$DataFrame(
  origin = c("ALG", "FRA", "GER"),
  year = c(2020, 2020, 2021)
)

test2 <- polars::pl$DataFrame(
  destination = c("USA", "JPN", "BRA"),
  language = c("english", "japanese", "portuguese")
)

test
#> shape: (3, 2)
#> ┌────────┬────────┐
#> │ origin ┆ year   │
#> │ ---    ┆ ---    │
#> │ str    ┆ f64    │
#> ╞════════╪════════╡
#> │ ALG    ┆ 2020.0 │
#> │ FRA    ┆ 2020.0 │
#> │ GER    ┆ 2021.0 │
#> └────────┴────────┘

test2
#> shape: (3, 2)
#> ┌─────────────┬────────────┐
#> │ destination ┆ language   │
#> │ ---         ┆ ---        │
#> │ str         ┆ str        │
#> ╞═════════════╪════════════╡
#> │ USA         ┆ english    │
#> │ JPN         ┆ japanese   │
#> │ BRA         ┆ portuguese │
#> └─────────────┴────────────┘

cross_join(test, test2)
#> shape: (9, 4)
#> ┌────────┬────────┬─────────────┬────────────┐
#> │ origin ┆ year   ┆ destination ┆ language   │
#> │ ---    ┆ ---    ┆ ---         ┆ ---        │
#> │ str    ┆ f64    ┆ str         ┆ str        │
#> ╞════════╪════════╪═════════════╪════════════╡
#> │ ALG    ┆ 2020.0 ┆ USA         ┆ english    │
#> │ ALG    ┆ 2020.0 ┆ JPN         ┆ japanese   │
#> │ ALG    ┆ 2020.0 ┆ BRA         ┆ portuguese │
#> │ FRA    ┆ 2020.0 ┆ USA         ┆ english    │
#> │ FRA    ┆ 2020.0 ┆ JPN         ┆ japanese   │
#> │ FRA    ┆ 2020.0 ┆ BRA         ┆ portuguese │
#> │ GER    ┆ 2021.0 ┆ USA         ┆ english    │
#> │ GER    ┆ 2021.0 ┆ JPN         ┆ japanese   │
#> │ GER    ┆ 2021.0 ┆ BRA         ┆ portuguese │
#> └────────┴────────┴─────────────┴────────────┘